With the development of the technology, fluctuations of the core voltage (Vcore) of a microprocessor (or called as a central processing unit) will affect operations of the microprocessor. If the core voltage is too high, it will increase the heat of the microprocessor, shorten the microprocessor's life expectancy, and even burn it down. On the contrary, if the core voltage is too low, it may cause data corruption, crashes, blue screens and other failures. As the core voltage of the microprocessor is getting higher and higher integration level, production processes become increasingly sophisticated, and the core voltage of the microprocessor is increasing, therefore, a power supply system having higher standards is required.
In the early stages, the motherboard commonly adopts a jumper or a dual inline package (hereinafter is referred to as DIP) switch to set the core voltage of the microprocessor. When installing or replacing the microprocessor, we must plug the jumper or toggle the DIP switch on the motherboard by reference to the core voltage of the microprocessor together with the specification of the motherboard so as to set the core voltage of the microprocessor. However, a slight mistake may burn down the microprocessor or the motherboard, which is very dangerous. In order to solve the abovementioned problem, Intel began to use a voltage identification technology (hereinafter is referred to as “VID”) from the Pentium II. The VID technology is a self-adaptive voltage regulation technology. After this technology is adopted, the power supply circuit of the motherboard is capable of automatically setting the desired power supply to the CPU, and manual intervention is not necessary anymore.
Later on, Intel introduces corresponding voltage regulation model (VRM) standards for various kinds of Intel's microprocessor products. Starting from the Prescott microprocessor, this voltage regulation standard is renamed as the voltage regulation down (VRD) standard. As for miscellaneous versions of the voltage regulation down standard, their VID bits, voltage regulation precisions, and regulation voltage ranges are different from each other. From all the reasons above, it is obvious that the microprocessor products with different voltage regulation standards need to operate in corresponding motherboards. Since each motherboard supports one kind of voltage regulation standard only, the motherboard is unable to mixed-use various microprocessor products having different voltage regulation standards.